Q: Which of the following is a correct statement about the energy conversion factor for electron-volts?

$$1\ \text{eV} = 1.6 \times 10$$^{-19}$$\ \text{J}$$

Question 1

A point charge $$q is $$placed at a distance $$r$$ from point $$P. $$What is the electric potential $$V at $$point $$P$$ due to this charge?

Accepted Answer

$$V = \frac{k_e q}{r}$$

Question 2

Which of the following statements about electric potential is correct?

Accepted Answer

Electric potential is a scalar quantity and can be summed directly for multiple point charges.

Question 3

A continuous charge distribution produces an electric potential at point $$P. $$Which integral correctly expresses the total potential at $$P$$?

Accepted Answer

$$V = \int \frac{k_e dq}{r}$$

Question 4

The electric potential energy $$U_{elec} of a $$charge $$q in an $$external electric potential $$V_{ext} is $$given by:

Accepted Answer

$$U_{elec} = q V_{ext}$$

Question 5

A system consists of four point charges $$q_1$$, $$q_2$$, $$q_3$$, $$q_4 at $$the corners of a square. Which expression gives the total electric potential energy of the system?

Accepted Answer

$$U = k_e \left( \frac{q_1$ q_2$}{r_{12}} + \frac{q_1$ q_3$}{r_{13}} + \frac{q_1$ q_4$}{r_{14}} + \frac{q_2$ q_3$}{r_{23}} + \frac{q_2$ q_4$}{r_{24}} + \frac{q_3$ q_4$}{r_{34}} \right)$$

Question 6

Which of the following best describes the relationship between electric field $$\vec{E}$$ and electric potential $$V$$?

Accepted Answer

$$\Delta V = - \int_{r_1$}^{r_2$} \vec{E} \cdot d\vec{s}$$

Question 7

A conductor is in electrostatic equilibrium. What can be said about the electric potential inside the conductor?

Accepted Answer

The electric potential is constant everywhere inside the conductor.

Question 8

A proton is released from rest in a region with a constant electric potential difference $$\Delta V. $$What is the final kinetic energy of the proton after moving through the potential difference?

Accepted Answer

$$KE = q \Delta V$$

Question 9

Which of the following is true about the work done by the electric field when moving a charge $$q$$ from point 1 to point 2?

Accepted Answer

$$W = -q (V_2$ - V_1$)$$

Question 10

A battery separates charge between two electrodes, creating a potential difference $$\Delta V. $$What is the direction of the electric field $$\vec{E}$$ between the electrodes?

Accepted Answer

From the positive electrode to the negative electrode

Question 11

If a charge $$q$$ moves from a region of higher potential $$V_1 to a $$region of lower potential $$V_2$$, what happens to its electric potential energy?

Accepted Answer

It decreases by $$q(V_1$ - V_2$)$$

Question 12

Which of the following is a correct statement about the energy conversion factor for electron-volts?

Accepted Answer

$$1\ 	ext{eV} = 1.6 	imes 10$$^{-19}$$\ 	ext{J}$$

Question 13

A charged particle moves through a region where only conservative forces act. Which of the following is true?

Accepted Answer

The sum of kinetic and potential energies remains constant.

Question 14

A spring with spring constant $$k is $$compressed by a distance $$x. $$What is the elastic potential energy stored in the spring?

Accepted Answer

$$U_{spring} = \frac{1}{2} k x^2$

Question 15

Which of the following is NOT a conservative force?

Accepted Answer

Friction

Question 16

A proton is accelerated from rest through a potential difference of $$1000\ 	ext{V}. $$What is its final speed? (Assume $$q = 1.6 	imes 10$$^{-19}$$\ 	ext{C}$$, $$m = 1.67 	imes 10$$^{-27}$$\ 	ext{kg})$$

Accepted Answer

$$v = \sqrt{\frac{2 q \Delta V}{m}}$$

Question 17

If the electric field $$\vec{E} is $$zero everywhere inside a conductor in electrostatic equilibrium, what can be said about the potential difference between any two points inside the conductor?

Accepted Answer

The potential difference is zero.

Electric Potential and Potential Energy

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